The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 30, 2013
Filed:
Jun. 06, 2012
Applicant:
Masaharu Fukakusa, Kumamoto, JP;
Inventor:
Masaharu Fukakusa, Kumamoto, JP;
Assignee:
Panasonic Corporation, Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B 7/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
In an optical pickup device for both CD and DVD disk media using a two-wavelength laser diode (), a diffraction grating () is commonly used for both laser beams (L, L) for CD and DVD to diffract each laser beam into a main beam and a pair of side beams. The diffraction grating includes a first diffraction grating region () and a second diffraction grating region () having a same pitch as the first diffraction grating region and being laterally offset from the first diffraction grating region, and at least one of the first and a second laser beams are diffracted by both of the first and second diffraction grating regions.